Abstract

Otto Friedrich Müller (1730–1784), Danish naturalist of the eighteenth century, was one of the founders of the Palearctic “continental” malacology, being the author of several tens of species and genera of land and aquatic molluscs described in his treatise “Vermium terrestrium et fluviatilium seu animalium infusorium, helminthicorum et testaceorum non marinorum succincta historia ” (1773–1774, 2 volumes). O. F. Müller’s contribution to systematic malacology still retains its high nomenclatorial significance but the current state of his collection as well as of type specimens of species described by him was unknown. The present paper is based on the examination of the remains of the müller’s malacological collection now being kept in the Natural History Museum of Denmark. We review its current state and provide illustrations of type specimens of 13 freshwater molluscan species described from the European waterbodies with remarks on their taxonomic position, nomenclature, and synonymy. Lectotypes for Planorbis albus, Planorbis imbricatus and Nerita fasciata are designated.